multidimensional-array - w3toppers.com

Maximum number of dimensions in a Java array

The Java language does not limit the number of dimensions, but the Java VM spec limits the number of dimensions to 255. For example, the following code will fail to compile: class Main { public static void main(String[] args) { final int[][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] [][][][][][][][][][][][][][][][] … Read more

How to cast simple pointer to a multidimensional-array of fixed size?

float (*somethingAsMatrix)[2] = (float (*)[2]) matrixReturnAsArray;

Multidimensional associative arrays in Bash

You can’t do what you’re trying to do: bash arrays are one-dimensional $ declare -A PERSONS $ declare -A PERSON $ PERSON[“FNAME”]=’John’ $ PERSON[“LNAME”]=’Andrew’ $ declare -p PERSON declare -A PERSON='([FNAME]=”John” [LNAME]=”Andrew” )’ $ PERSONS[1]=([FNAME]=”John” [LNAME]=”Andrew” ) bash: PERSONS[1]: cannot assign list to array member You can fake multidimensionality by composing a suitable array index … Read more

Is array syntax using square brackets in URL query strings valid?

The answer is not simple. The following is extracted from section 3.2.2 of RFC 3986 : A host identified by an Internet Protocol literal address, version 6 [RFC3513] or later, is distinguished by enclosing the IP literal within square brackets (“[” and “]”). This is the only place where square bracket characters are allowed in … Read more

Why do these two javascript 2d-arrays behave differently?

That’s because in case of array1 it contains three arrays, but all three of them point to the same reference variable, that was evaluated when new Array(n) was executed: var array1 = new Array(n).fill(new Array(n)); So when the for loop runs over array1 it is setting the value of the same array reference, while in … Read more

PHP: Check for duplicate values in a multidimensional array

This will remove duplicate items from your array using array_unique(): $new_arr = array_unique($arr, SORT_REGULAR);

How to copy a row of values from a 2D array into a 1D array?

The following code demonstrates copying 16 bytes (4 ints) from a 2-D array to a 1-D array. int[,] oGridCells = {{1, 2}, {3, 4}}; int[] oResult = new int[4]; System.Buffer.BlockCopy(oGridCells, 0, oResult, 0, 16); You can also selectively copy just 1 row from the array by providing the correct byte offsets. This example copies the … Read more

Connected Component Labeling – Implementation

I’ll first give you the code and then explain it a bit: // direction vectors const int dx[] = {+1, 0, -1, 0}; const int dy[] = {0, +1, 0, -1}; // matrix dimensions int row_count; int col_count; // the input matrix int m[MAX][MAX]; // the labels, 0 means unlabeled int label[MAX][MAX]; void dfs(int x, … Read more

How to convert a 3d numpy array to 2d

In [27]: x = np.arange(16).reshape((4,2,2)) In [28]: x.reshape(2,2,2,2).swapaxes(1,2).reshape(4,-1) Out[28]: array([[ 0, 1, 4, 5], [ 2, 3, 6, 7], [ 8, 9, 12, 13], [10, 11, 14, 15]]) I’ve posted more general functions for reshaping/unshaping arrays into blocks, here.

Convert delimited string into array key path and assign value

This is kind of non-trivial because you want to nest, but it should go something like: function insert_using_keys($arr, $keys, $value){ // we’re modifying a copy of $arr, but here // we obtain a reference to it. we move the // reference in order to set the values. $a = &$arr; while( count($keys) > 0 ){ … Read more